iio:trigger: rename try_reenable() to reenable() plus return void

As we no longer support a try again if we cannot reenable the trigger
rename the function to reflect this.   Also we don't do anything with
the value returned so stop it returning anything.  For the few drivers
that didn't already print an error message in this patch, add such
a print.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: Christian Oder <me@myself5.de>
Cc: Eugen Hristev <eugen.hristev@microchip.com>
Cc: Nishant Malpani <nish.malpani25@gmail.com>
Cc: Daniel Baluta <daniel.baluta@oss.nxp.com>
Link: https://lore.kernel.org/r/20200920132548.196452-3-jic23@kernel.org